1. Field of the Invention
The present invention relates to an ink-jet recording apparatus in which insoluble materials originating from rubber members employed in an ink passage are prevented from precipitating into a preservation solution or a water-based ink filled into the ink passage.
2. Description of the Related Art
An ink-jet recording apparatus is an apparatus for performing recording by causing ink to adhere to a recording material such as recording paper by means of an ink ejection method such as a bubble method or a piezo method. In the bubble method, ink is rapidly heated to generate bubbles, and fine droplets of the ink are ejected from fine nozzles by utilizing the pressure generated by the rapid heating. In the piezo method, fine droplets of ink are ejected by use of a piezoelectric element.
In an ink-jet recording apparatus, rubber members are employed in an ink passage comprised of e.g., an ink tank and an ink-jet head. These rubber members include a cap which covers nozzles of the ink-jet head, a wiper which cleans the end face of the nozzles of the ink-jet head, a seal packing which is placed at the joint portion between components, and the like. In addition, if the ink tank is provided separately from the ink-jet head, the rubber members also include a tube which supplies ink from the ink tank to the ink-jet head, and the like.
However, when the rubber members come in contact with a preservation solution filled into an ink passage at the time of shipping or during long-term storage or with a water-based ink employed in ink-jet recording, the additives contained in the rubber members are dissolved in the preservation solution or the water-based ink. The dissolved additives then precipitate as an insoluble material, thereby causing a problem such as clogging of nozzles of an ink-jet head.
In view of the above, a method has been proposed in US-A1-20050116984. In this method, rubber materials to be employed in an ink passage are immersed in water at 60° C. for a predetermined time in a sealed container for determining the amount of dissolved materials to thereby select suitable rubber materials.
However, the amounts and kinds of the insoluble materials precipitating into a preservation solution or an ink depend on the composition of the preservation solution or the ink. Therefore, even when the rubber materials selected by means of the method of US-A1-20050116984 are employed in the rubber members forming the ink passage, the problem of the precipitation of the insoluble materials occasionally arises. Specifically, the problem may arise when the composition of the preservation solution is adjusted such that the preservation solution has a dynamic surface tension preferable for replaceability with the ink and wettability and when the composition of the ink is adjusted such that the ink has a dynamic surface tension preferable for ejection stability.